libjava/classpath/java/awt/Menu.java

   1 /* Menu.java -- A Java AWT Menu
   2    Copyright (C) 1999, 2002, 2004, 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt;
  40
  41 import java.awt.peer.MenuPeer;
  42 import java.io.Serializable;
  43 import java.util.Enumeration;
  44 import java.util.Vector;
  45
  46 import javax.accessibility.AccessibleContext;
  47 import javax.accessibility.AccessibleRole;
  48
  49 /**
  50   * This class represents a pull down or tear off menu in Java's AWT.
  51   *
  52   * @author Aaron M. Renn (arenn@urbanophile.com)
  53   */
  54 public class Menu extends MenuItem implements MenuContainer, Serializable
  55 {
  56
  57 /*
  58  * Static Variables
  59  */
  60
  61 // Serialization Constant
  62 private static final long serialVersionUID = -8809584163345499784L;
  63
  64 /*************************************************************************/
  65
  66 /*
  67  * Instance Variables
  68  */
  69
  70 /**
  71   * @serial The actual items in the menu
  72   */
  73 private Vector items = new Vector();
  74
  75 /**
  76   * @serial Flag indicating whether or not this menu is a tear off
  77   */
  78 private boolean tearOff;
  79
  80 /**
  81   * @serial Indicates whether or not this is a help menu.
  82   */
  83 private boolean isHelpMenu;
  84
  85   /*
  86    * @serial Unused in this implementation, but present in Sun's
  87    * serialization spec.  Value obtained via reflection.
  88    */
  89   private int menuSerializedDataVersion = 1;
  90
  91 static final transient String separatorLabel = "-";
  92
  93 /*************************************************************************/
  94
  95 /*
  96  * Constructors
  97  */
  98
  99 /**
 100   * Initializes a new instance of <code>Menu</code> with no label and that
 101   * is not a tearoff;
 102   *
 103   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 104   */
 105 public
 106 Menu()
 107 {
 108 }
 109
 110 /*************************************************************************/
 111
 112 /**
 113   * Initializes a new instance of <code>Menu</code> that is not a tearoff and
 114   * that has the specified label.
 115   *
 116   * @param label The menu label.
 117   *
 118   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 119   */
 120 public
 121 Menu(String label)
 122 {
 123   this(label, false);
 124 }
 125
 126 /*************************************************************************/
 127
 128 /**
 129   * Initializes a new instance of <code>Menu</code> with the specified
 130   * label and tearoff status.
 131   *
 132   * @param label The label for this menu
 133   * @param isTearOff <code>true</code> if this menu is a tear off menu,
 134   * <code>false</code> otherwise.
 135   *
 136   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
 137   */
 138 public
 139 Menu(String label, boolean isTearOff)
 140 {
 141   super(label);
 142
 143   tearOff = isTearOff;
 144
 145   if (label.equals("Help"))
 146     isHelpMenu = true;
 147
 148   if (GraphicsEnvironment.isHeadless())
 149     throw new HeadlessException ();
 150 }
 151
 152 /*************************************************************************/
 153
 154 /*
 155  * Instance Methods
 156  */
 157
 158 /**
 159   * Tests whether or not this menu is a tearoff.
 160   *
 161   * @return <code>true</code> if this menu is a tearoff, <code>false</code>
 162   * otherwise.
 163   */
 164 public boolean
 165 isTearOff()
 166 {
 167   return(tearOff);
 168 }
 169
 170 /*************************************************************************/
 171
 172 /**
 173   * Returns the number of items in this menu.
 174   *
 175   * @return The number of items in this menu.
 176   */
 177 public int
 178 getItemCount()
 179 {
 180   return countItems ();
 181 }
 182
 183 /**
 184  * Returns the number of items in this menu.
 185  *
 186  * @return The number of items in this menu.
 187  *
 188  * @deprecated As of JDK 1.1, replaced by getItemCount().
 189  */
 190 public int countItems ()
 191 {
 192   return items.size ();
 193 }
 194
 195 /*************************************************************************/
 196
 197 /**
 198   * Returns the item at the specified index.
 199   *
 200   * @return The item at the specified index.
 201   *
 202   * @exception ArrayIndexOutOfBoundsException If the index value is not valid.
 203   */
 204 public MenuItem
 205 getItem(int index)
 206 {
 207   return((MenuItem)items.elementAt(index));
 208 }
 209
 210 /*************************************************************************/
 211
 212 /**
 213   * Adds the specified item to this menu.  If it was previously part of
 214   * another menu, it is first removed from that menu.
 215   *
 216   * @param item The new item to add.
 217   *
 218   * @return The item that was added.
 219   */
 220 public MenuItem
 221 add(MenuItem item)
 222 {
 223   MenuContainer parent = item.getParent();
 224   if (parent != null)
 225     parent.remove(item);
 226
 227   items.addElement(item);
 228   item.setParent(this);
 229
 230   if (peer != null)
 231     {
 232       item.addNotify();
 233       MenuPeer mp = (MenuPeer) peer;
 234       mp.addItem(item);
 235     }
 236
 237   return item;
 238 }
 239
 240 /*************************************************************************/
 241
 242 /**
 243   * Add an item with the specified label to this menu.
 244   *
 245   * @param label The label of the menu item to add.
 246   */
 247 public void
 248 add(String label)
 249 {
 250   add(new MenuItem(label));
 251 }
 252
 253 /*************************************************************************/
 254
 255 /**
 256   * Inserts the specified menu item into this menu at the specified index.
 257   *
 258   * @param item The menu item to add.
 259   * @param index The index of the menu item.
 260   *
 261   * @exception IllegalArgumentException If the index is less than zero.
 262   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 263   */
 264 public void
 265 insert(MenuItem item, int index)
 266 {
 267   if (index < 0)
 268     throw new IllegalArgumentException("Index is less than zero");
 269
 270   int count = getItemCount ();
 271
 272   if (index >= count)
 273     add(item);
 274   else
 275     {
 276       MenuContainer parent = item.getParent();
 277       if (parent != null)
 278         parent.remove(item);
 279
 280       items.insertElementAt(item, index);
 281       item.setParent(this);
 282
 283       MenuPeer peer = (MenuPeer) getPeer();
 284       if (peer == null)
 285         return;
 286
 287       for (int i = count - 1; i >= index; i--)
 288         peer.delItem(i);
 289
 290       item.addNotify();
 291       peer.addItem(item);
 292
 293       for (int i = index; i < count; i++)
 294         peer.addItem((MenuItem) items.elementAt (i));
 295     }
 296
 297 }
 298
 299 /*************************************************************************/
 300
 301 /**
 302   * Inserts an item with the specified label into this menu at the specified index.
 303   *
 304   * @param label The label of the item to add.
 305   * @param index The index of the menu item.
 306   *
 307   * @exception IllegalArgumentException If the index is less than zero.
 308   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 309   */
 310 public void
 311 insert(String label, int index)
 312 {
 313   insert(new MenuItem(label), index);
 314 }
 315
 316 /*************************************************************************/
 317
 318 /**
 319   * Adds a separator bar at the current menu location.
 320   */
 321 public void
 322 addSeparator()
 323 {
 324   add(new MenuItem(separatorLabel));
 325 }
 326
 327 /*************************************************************************/
 328
 329 /**
 330   * Inserts a separator bar at the specified index value.
 331   *
 332   * @param index The index at which to insert a separator bar.
 333   *
 334   * @exception IllegalArgumentException If the index is less than zero.
 335   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 336   */
 337 public void
 338 insertSeparator(int index)
 339 {
 340   insert(new MenuItem(separatorLabel), index);
 341 }
 342
 343 /*************************************************************************/
 344
 345 /**
 346   * Deletes the item at the specified index from this menu.
 347   *
 348   * @param index The index of the item to remove.
 349   *
 350   * @exception ArrayIndexOutOfBoundsException If the index is otherwise invalid.
 351   */
 352 public synchronized void
 353 remove(int index)
 354 {
 355   MenuItem item = (MenuItem) items.remove(index);
 356
 357   MenuPeer mp = (MenuPeer) getPeer();
 358   if (mp != null)
 359     {
 360       mp.delItem(index);
 361       item.removeNotify();
 362     }
 363   item.setParent(null);
 364 }
 365
 366 /*************************************************************************/
 367
 368 /**
 369   * Removes the specifed item from the menu.  If the specified component
 370   * does not exist, this method does nothing.
 371   *
 372   * @param item The component to remove.
 373   */
 374 public void
 375 remove(MenuComponent item)
 376 {
 377   int index = items.indexOf(item);
 378   if (index == -1)
 379     return;
 380
 381   remove(index);
 382 }
 383
 384 /*************************************************************************/
 385
 386 /**
 387   * Removes all the elements from this menu.
 388   */
 389 public synchronized void
 390 removeAll()
 391 {
 392   int count = getItemCount();
 393   for(int i = 0; i < count; i++)
 394     {
 395       // We must always remove item 0.
 396       remove(0);
 397     }
 398 }
 399
 400 /*************************************************************************/
 401
 402 /**
 403   * Creates the native peer for this object.
 404   */
 405 public void
 406 addNotify()
 407 {
 408   MenuPeer peer = (MenuPeer) getPeer();
 409   if (peer == null)
 410     {
 411       peer = getToolkit().createMenu(this);
 412       setPeer(peer);
 413     }
 414
 415   Enumeration e = items.elements();
 416   while (e.hasMoreElements())
 417   {
 418     MenuItem mi = (MenuItem)e.nextElement();
 419     mi.addNotify();
 420     peer.addItem(mi);
 421   }
 422
 423   super.addNotify ();
 424 }
 425
 426 /*************************************************************************/
 427
 428 /**
 429   * Destroys the native peer for this object.
 430   */
 431 public void
 432 removeNotify()
 433 {
 434   Enumeration e = items.elements();
 435   while (e.hasMoreElements())
 436   {
 437     MenuItem mi = (MenuItem) e.nextElement();
 438     mi.removeNotify();
 439   }
 440   super.removeNotify();
 441 }
 442
 443 /*************************************************************************/
 444
 445 /**
 446   * Returns a debugging string for this menu.
 447   *
 448   * @return A debugging string for this menu.
 449   */
 450 public String
 451 paramString()
 452 {
 453   return (",tearOff=" + tearOff + ",isHelpMenu=" + isHelpMenu
 454           + super.paramString());
 455 }
 456
 457   /**
 458    * Basic Accessibility class for Menu.  Details get provided in derived
 459    * classes.
 460    */
 461   protected class AccessibleAWTMenu extends AccessibleAWTMenuItem
 462   {
 463     private static final long serialVersionUID = 5228160894980069094L;
 464
 465     protected AccessibleAWTMenu()
 466     {
 467     }
 468
 469     public AccessibleRole getAccessibleRole()
 470     {
 471       return AccessibleRole.MENU;
 472     }
 473   }
 474
 475   /**
 476    * Gets the AccessibleContext associated with this <code>Menu</code>.
 477    * The context is created, if necessary.
 478    *
 479    * @return the associated context
 480    */
 481   public AccessibleContext getAccessibleContext()
 482   {
 483     /* Create the context if this is the first request */
 484     if (accessibleContext == null)
 485       accessibleContext = new AccessibleAWTMenu();
 486     return accessibleContext;
 487   }
 488
 489 } // class Menu